Instruments of different technological complexities can be used to navigate at sea. The most basic navigational tools include nautical charts in paper form, compasses and basic speed meters on the ship, while the more complex tools include chart plotters linked to GPS receivers and interfaces for connecting to Satcoms and/or for connecting to the Internet to obtain up-to-date metrological data.
Usually, a separate user interface is provided for each navigation device. For example, on the ship, there may be provided one display showing the depth from the hull to the seabed, another display showing the speed of the vessel relative to the ocean current and a third display interfacing to a conventional radar unit. Some attempts have been made to integrate the different devices. For example, the National Marine Electronics Association (NMEA) has developed an interface, which can communicate with a number of different conventional sensors. However, even if the data is presented together, it is typically only combined on a display and the data from the different sensors is typically not processed together.
Moreover, the user-friendliness of conventional interfaces and the detail of the information provided to the end-user are often not satisfactory. For example, a traditional user interface to radar sensors commonly displays a large cluster point on a screen to represent a large backscattered return from a large object in the vicinity of the ship and a small cluster point on a screen to represent a smaller backscattered return from a smaller object. Moreover, the point only conveys the object's distance relative to the radar sensor. As the radar turns 360 degrees, a full representation of all visible objects can be mapped on the screen. However, there is no possibility of investigating the object further such as investigating whether the object is a buoy or a swimmer. Moreover, the screen does not typically give the end-user a quick overview of the heading and speed of the object in relation to the ship.
Similarly, sonar technology is often used merely to show the depth in one dimension, i.e. the distance to the seabed directly below a single transducer on the ship. Consequently, it does not signal forward hazards such as rocks to the user. Forward-looking sonar heads have now been developed but they do not provide depth data coherently with range and bearing information.
Video and infrared cameras have been used for security purposes to protect against potential intruders approaching a ship. However, various objects can approach the ship without being detected by these systems, particularly in fog, during the night or when the objects approach below the surface of the water.
Traditional sensors and instrumentation on marine vessels do not adequately protect goods and people. They are not capable of detecting, tracking and providing details about events such as goods and people falling overboard.
The invention aims to address these and other issues.